1. Field of the Invention
This invention relates to thrust engine systems, and is particularly directed to a hybrid staged combustion-expander topping cycle engine.
2. Description of the Prior Art
In the thrust engine, basically a set of propellants is pumped through a combustor and burn therein to provide thrust. Some of these engines are known as gas generators and some are staged combustion cycle engines. Staged combustion cycle engines are very high chamber pressure engines providing a large thrust. Thus they operate at very high system pressure and very high system temperatures.
In a typical staged combustion cycle engine, both the fuel turbine and the oxidizer turbine are driven by preburners employing very high temperature gasses, of the order of 1900.degree. R. In such fully staged combustion cycles there is thus employed two preburners, one for each of the respective turbines. The gasses discharged from the turbines are combined and are introduced at very high temperatures into the thrust chamber of the engine.
As between the gas generator cycle engine and the staged combustion engine, the latter is of higher performance. However, because of the high temperatures and pressures involved in the staged combustion engine and due to the presence of more components in such engines and high thermal stresses in the turbines, a greater potential for failure is present, thus reducing the reliability potential for such engines.